A robotic pool cleaner drives around inside your pool on its own, vacuuming the floor, scrubbing the walls and, on better models, working the greasy band at water level. It runs on its own motor and its own filter, so it does not depend on your pump or your skimmer, and it takes debris out of the water instead of pushing it towards the filtration system. It is the outdoor sibling of the Robot Vacuums and Robot Lawn Mowers already in this catalog.
The category changed shape in the last few seasons. For twenty years a pool robot meant a heavy corded box from a pool-industry brand; then the consumer robotics makers arrived with battery models, cameras, sonar and apps, and prices split into a range that runs from a couple of hundred to well over three thousand. Two cleaners at the same price can now differ by an hour of runtime, by whether they touch the waterline at all, and by whether they finish where you can reach them.
Corded or cordless is the first decision
Everything else follows from this one. A Cordless cleaner has no floating cable and no transformer at the pool edge, which is the only option when there is no outlet nearby. The trade-off is that a cycle ends when the charge does: check Battery Life for the mode you actually want, because floor-only runtime is usually around twice what the same robot manages with walls and waterline added. Charging Time is longer than the runtime, three to five hours, so a cordless robot is a once-a-day machine.
A corded model keeps going as long as the cycle lasts and moves more water for the same money, which is why a corded unit is still the best seller in the category. Its limit is not the pump but the Cable Length: it has to reach the farthest corner with slack to spare, and a cable without a swivel twists and stops the robot short.
A Charging Dock removes the exposed pins that corrode in a wet chlorinated environment. Solar Charging belongs to a different machine altogether: floating skimmers that recharge in the sun and run unattended, collecting leaves and pollen while they still float, which is when they are cheapest to remove.
What the robot actually cleans
Read the coverage rows as a ladder. Floor Cleaning is the baseline every submersible robot does. Wall Cleaning is the first real step up, because walls are where algae takes hold and climbing needs enough suction to hold the robot against a vertical surface. Waterline Cleaning is the job people hate doing by hand, the tide line of sunscreen and body oils at water level: harder than climbing, since the machine has to hold a constant depth and scrub sideways, and the clearest line between a mid-range and a premium model.
Water Surface Skimming is answered YES by two very different machines: solar skimmers that only float, and flagships that spend part of their cycle at the surface. Steps & Platform Cleaning is the hardest of all, since a tanning ledge may be only twenty centimetres under water.
Suction Power in gallons per hour is a class indicator rather than a measured result, since every maker quotes it in the friendliest mode with a clean filter, but the range is real: entry-level above-ground units move around two thousand gallons per hour and flagships more than eight thousand. The Brush System removes what has stuck to the surface, which suction alone never does. Edge & Corner Cleaning covers the cove where floor meets wall, and Cleaning Modes decides how finely you can spend a charge.
How it finds its way
Navigation Type decides whether a cycle covers the whole pool or leaves patches. Random models cover a small pool by luck and burn a whole charge doing it; mapped models drive in lanes and finish sooner, which matters far more on a battery than on a cable. Ultrasonic Mapping measures the pool with sonar and works where a camera struggles, in cloudy water and at night, while AI Camera Vision lets a robot drive towards the dirt. Obstacle Avoidance keeps it from wedging under the ladder, which ends a cycle silently and leaves half the pool untouched.
Two navigation features are about your back. Auto Parking sends the robot to the waterline when the cycle ends, so you can reach it without a pole. Self-Docking returns it to a dock to recharge without being lifted out at all, the newest and most expensive idea in the category.
Filtration is what you live with
The filter is the part you touch after every cycle, so it decides whether the robot keeps getting used. Filter Capacity sets how often you empty it: a small basket fills up mid-cycle in autumn while the machine keeps driving with no suction left. Filter Fineness in microns says what it traps, from coarse media around 180 microns for leaves to fine media between three and fifty microns for pollen, algae and silt. A Dual-Layer Filter runs both at once, the only way to hold suction for a whole cycle without letting fine dirt back into the pool.
Two small features matter more than their price suggests. A Top-Access Basket is emptied from above with the unit still on the coping, instead of flipping a dripping robot over on the deck. A Filter Full Alert catches the failure nothing else shows: a clogged basket loses most of its suction while the cycle finishes looking perfectly normal.
Match it to your pool, not to the brochure
In-Ground Pools and Above-Ground Pools are different jobs: above-ground pools have soft liners, a flat floor and almost no wall to climb, and not every in-ground robot is safe on that liner. Max Pool Area is quoted per cycle in the easiest mode, so a rating of roughly twice your surface leaves margin for walls and waterline. A 16 by 32 foot rectangle is about five hundred square feet, which puts most residential pools under a thousand.
Then check the Weight, the spec owners underrate most. The robot comes out several kilos heavier than its dry figure because it carries water, and it has to clear the coping every cycle. Anything above twelve kilos dry is a two-hand lift, which is exactly why auto parking and docking exist.
The smart home part
Water blocks radio almost completely, so a submerged pool robot cannot hold a Wi-Fi or Bluetooth link. Makers use the connection while the unit is at the surface or docked, to schedule cycles and report results, and some add a floating gateway to keep it alive mid-cycle. That is also why underwater remotes use LiFi, sending commands as light through the water, which shows up in the Other connectivity row.
App Control is where Scheduling, modes and cleaning history live, and plenty of corded and entry-level units have none: you press a button and get whatever cycle it shipped with. Manual Remote Control is how you send the machine to one spot after a storm. Ecosystem support is thinner here than anywhere else in this catalog, so check it rather than assume: the pool-industry platforms are the ones that reach Alexa and Google Home, while most cordless brands stay inside their own app. To automate the pool beyond the robot, the pump is the better target, through the Plugs and Energy Monitors categories.
Finally, read the Warranty as a spec, not as paperwork. A pool robot lives submerged in chlorinated water, and the term a maker offers, from one year to three, is one of the few public signals of how it expects the seals, the motors and the battery to age.
